Gas heating structure



March 2, 1965 R. E. CARLSON GAS HEATING STRUCTURE 2 Sheets-Sheet 1 FiledJune 11, 1962 @/cA/Qeo 5. 00em/v I N VEN TOR.

,qroe/va/ United States Patent Cflce 3,l7l,402' Patented Mar. 2, 19653,171,492 GAS HEATING STRUCTURE Richard E. Carlson, '768 N. AlmansorSt., Alhambra, Calif. Filed .lune lll, i962, Ser. No. Zlllflll 6 Claims.G3i. l26-ll6) This invention relates to gas lired heaters with sealedcombustion chambers especially for house trailers, cabins, yachts,homes, cabin cruisers, sailboats and the like. With such heaters,combustion air to supply the gas burners in the sealed combustionchambers is drawn `from the outside air rather than from the interiorsof the spaces being heated. With such heaters it is also the practice tovent the combustion chambers laterally from the upper portions thereofout through the buildings sidewalls, and to draw the outside combustionair through a concentric air pipe surrounding the vent pipe.

Lateral venting with concentric horizontal piping lhas heretofore beendeemed to be the only satisfactory construction for heaters with sealedcombustion chambers, apparently because it has been thought that freshcombustion air how to the combustion chamber could be satisfactorilyaccomplished only by horizontal how from the exterior of the structureto be heated.

However, such heater constructions have various objections, includingside-wall venting, Variable draft conditions, and hot vent caps at lowlevels outside.

It is a general object of this invention to provide a space heater whicheliminates all such objections and adds desirable features.

It is a particularly object of this invention to provide a space heatingstructure which is vented through the roof and at the same time retainsthe concentric piping arrangement, the outside combustion air beingbrought down around the hot vent pipe from a position above the roof andinto the lower portion of the combustion chamber.

A further Object of the invention is to produce a gas red heaterstructure with which the heating capacity may be increased materiallywithout enlarging either the structure of the heater or its burner, thetop of the heater structure extending through the roof, the combustiongases being vented from the top of the combustion chamber through aninner vent pipe, and the outside combustion air being brought down intothe bottom of the combustion chamber through an outer concentric airpipe.

Still another object of the invention is to transfer the typical ventcap to an elevated position so that such vent cap, which often becomesquite hot, is not in a position to burn persons passing the side of thebuilding, as where horizontal piping is vented.

A stillfurther object of the invention is to increase the efficiency ofsuch a heater f a given size over that attained by horizontal ventingand piping, by employing vertical venting and piping whereby to improvedraft conditions for the heater, the draft being in some mannerpartially choked where horizontal venting and piping are employed, suchchoking disappearing with the present vertical venting and pipingsystem.

A still further object is to provide a vertical venting and pipingarrangement extending through the roof wherein a vent cap structure isemployed which not only diverts rain or water spray from entering theexhaust venting pipe, but also covers the cool air intake pipe to guideit against the entry of rain or spray.

An additional object of the invention is t-o provide a gas fired spaceheater which may be located in an interior wall, the venting and pipingarrangement through the roof making possible such interior location, asdistinguished from the enforced location of a similar heater adjacent anouter Wall when the piping and Venting are horizontally disposed.

Briefly outlined, the present improvement inc.udes an upstandingtwo-element heating member disposed vertically in a shallow casing orhousing often known as a linen The forward element of the heating memberconstitutes a sealed re box or combustion chamber at the lower end ofwhich a burner is positioned and at the upper end of which there is anoutlet passage to a vertical ilue or vent pipe mounted on the heatingmember and extending up through the buildings roof to vent thecombustion gases. The other element of the heating member' is aflattened air chamber element disposed behind the lire box or combustionchamber, both elements being `attached to an intervening radiationpartition. This ilattened chamber element is in the form of an airsupply chamber enclosed on all sides and at its top and bottom, exceptthat its top provides an intake opening for cool air and its forwardwall at the bottom provides an opening connected by an air duct to thelower portion of the combustion chamber to feed such cool air to theburner to support combustion. The upper end of the air chamber isprovided with an air intake duct which leads downward from an annularspace wit in a collar upstanding from the heater member and receivingthe lower end of an outer concentric air intake pipe leading down fromthe roof around the exhaust pipe. Above the roof, the top or" theexhaust pipe carries a vent cap under which the spent combustion gasesare discharged, such cap excluding rain or spray from the exhaust pipeand also overlying the upper end of the air intake pipe to exclude raintherefrom. Thus, pre-warmed cool air is fed from above the roof downthrough the annular space between the exhaust pipe and the air intairepipe Where it enters the upper end of the air chamber whence it passesto the lower end of the combustion chamber, the spent combustion gasesthen rising through the outlet from the combustion chamber into thecentral exhaust pipe by which they are ydischarged through the roof.Convection air rises around the combustion chamber in front of theradiation partition, and also rises around the intake air chamber whichis heated by radiation from the combustion chamber via the radiationpartition, such heated air passing forward and outward through the upperportion of a grill or front panel into the living space of the building,radiation heat being projected directly forward from the combustionchamber .through the grill into such living space.

Further objects and features of the invention will become apparent tothose skilled in the art upon reference to the following specication andthe accompanying drawings wherein a presently preferred form of theinvention is disclosed.

In the drawings:

FlG. l is a perspective view of the heating structure of this inventiondisclosed as installed in a wall of a small building, portions of thewall being broken away;

FIG. 2 is a vertical section from front to back taken as indicated bythe line 2 2 of FIG. l;

FIG. 3 is a front elevation of the heating element as indicated by theline 3 3 of FIG. 2, the grill being removed and a portion of the frontWall of the combustion chamber being broken away;

FIG. 4 is a cross-sectional detail taken on the line 4 4 of FIG. 3;

FIG. 5 is a cross section taken on the line 5 5 of FlG. 3; and

FIG. 6 is a fragmentary cross section taken from the line 6 6 of FIG. 3.

The present improvement is shown especially in the upper portions ofFIGURES l and 2, which illustrate the arrangement of the air supply andexhaust pipes upstanding from the top of the heater and in theirrelationship to the upper portions of the heater elements.

As indicated, the entire heating structure is arranged for installationwithin a wall of a house traileror the like in which it is to be used.Whereas laterally vented gas Yheaters must be disposed in an outer wall,the present structure, being vented through the roof, may be mounted inan interior wall.

With particular reference to the drawings, a wall strueture isillustrated as including a typical rearward wall panel 1t), a forward orinner wall panel i2, a roof panel Y 14 or other roof structure, and apair of upstanding supl- Y porting and spacing studs 15, all of whichare carried on an appropriate oor structure i8.

A primary heating member or unit generally indicated at.20, which isillustrated asan upstanrlingV gas fired sheet metal structure, issupported in .a rectangular housing or 28 affording an annularcold-airlconducting channel Desirably there is also an interveningconcentric radiation pipe 32 which provides an inner annular air channel34, whereby further to reduce the tempera-ture of the air pipe28. Thesepipes 26, 28, and32 are iixediy carried by the top of the heater unit20.

' The heater unit 20 includes two spaced upstanding connected elements.The forward element 35 provides an enf closed combustion chamber36having a forward upper wall portion parallel to forward and rearwardparallel walls of a rearwardY element 38 vwhich-provides an enclosedcold-air supplying chamber 39. Both of these elements 35 and 38 are, ingeneral, rectangular in design similar to the rectangular constructionof the housing 22,

" tions 54C.

:port 4S the airV chamber 39 in the rearward element 38 is supplied.Thus, the approximately square plate 54 affords ywithin thercollar 56 anarrow forward shelf 54a, as indicated in FIG. 4, .which is immediatelyforward of kthe Vent pipe 26V and ,desirably tangentially contactedthereby. Lateral shelves 54b are similarly formed. The inward edges ofthese shelves are welded to the top edges of the vertical walls of thebox 44, as are the outlying por- In order to centralizethe lower end ofthe radiation pipe 32, a set of spring spacing clips 68 is provided,either on 4the inner wall of the collar v56,-or mounted on the lower endof the radiation pipe 32 as shown.

For mounting .the upper end of the outer air pipe 28 in the roof 14, acollar 62jiianged at 62a, as seen in FIGS. l and 2, Iis mounted andcalked at 61 on .top of the roof 14, and an upper end portion of theouter air- L pipe 28 extending above the roof is within .the collar.

but they are appreciably smaller in order to be mounted in spacedrelation in the housing 22 andprovide adequate rigid connection is madethrough the medium of a connecting air tube 40 welded to the opposingwalls of the two elements and providing a duct to feed coo-l air fromthe lower end of the air passage or chamber 39 to, the lower end ofthefcombustion chamber 36 which contains at such lower end a burner 42of `any desired construction. The upper portion of the burner isdisposed between two opposed bafiles 43 which control the flame. Theupper ends of the elements and 36 are rigidly connected by weldingthereto a metal rectangular approximately cubical box 44 (FIG. 6) whosebottom wall 45 is provided with a circular opening constituting a port46 around which is welded to the bottom 45 the lower end portion of theexhaust pipe 26. Rearward of the circular port 46, the bottom 45 of suchbox is also provided with a transverse rectangular opening constitutingan inlet port 48 which provides an air feed passage into they top of the'Y air chamber 39 of the rearward element 38.

As probably best seen in FIG. 5, the rearward element 38 provides avertical elongated rectangular passage con- Y stituting the air chamber39 formed between a back wall 50 and a front wall 51 of the element 38,such passage extending from the inlet port 48 down to the discharge Theback This collar 62 which thus also surrounds the upper ends of the ventpipe 26 and the radiation pipe 32, acts to 'cen- -ter the pipe 28m thecorresponding roof opening 63.

yThe vent cap V25 is VshownV as including a short cylinder 64 which actsas a wind-guard and is carried-around an upwardly tapered rain-sheddingcap `65 insuitably spaced relation by spring clipsY 66 or Ytheilike.-This tapered or conical cap 65 acts toV distribute the spent gasesrising through the vent pipe 26, and also `to exclude rain from the pipe26 as well as from the pipes 28and 32. For these purposes a sleevemember 68 depends in suitable relationship below the tapered cap 65,' asby depending directly from a spaced large integral flange or annularplate 70 connected to theunderside of the tapered cap 65 byr spacingclips *'72 or the like. VThe sleeve 68 tits over the upper end of thevent pipe'26, any appropriate spacing means, such as spring clips 73being employed to retain concentric relationships between the sleeve 68,the pipe 26 and the pipe 32. `The, upper end of the collar 62 is securedby clips .74 to the plate 70-which thus irnparts concentricity of thekpipes 26 and 32 with the outer pipe 28.l Of these pipes, the vent pipe26 is the longest and reaches the plate 70. The V.outer pipe 28 is theshortest and suppliesrcombustion air. The pipe'32 is intermediate inlengthas shown.

By such means, spent combustion gases rising through the vent pipe 26are dischargedabove the plate 70 and below the cap 65, and cool air isreceived throughA the annular channels 30 and 34, which air descendsthrough the openings 48'1and 58 `to feed the fresh air to the chamber 39in the rearward heating element 38 and supply the burner k42V by way ofthe duct 40 Vleading to the lower end of the combustion chamber 36, asvpreviously indicated. Y Y l In the particular form ofheater'illustrated, the combustion element 35 includes a perpendicularrear wall 75 (approximately aligned withr the forward wall of the i aVbox 44) and aY forward wall 76 which desirably includes way ofthe-rectangular port 48 and thencevia the duct y has welded on the topthereof a collar 56 over which the' lower end of the outer air pipe 28ts, as seen in FIGS.

a downwardly and outwardly sloping portion 77 so that the lower portionof ythe combustion chamber 36 is somewhat enlarged. Near the upper endof the chamber 36 a baie 78 is disposed/in transverse relationshipwhereby to deflect the spent combustionV gases laterally around its ends(which, as seen in FIG; 3, are spaced from the side walls-79 of Itheelement 35) and facilitate heatabsorption by the walls of the heaterelement 35, as well as icontrol draft. At the middle upper portion ofthe back wall 75, an outlet 80 is provided above the baie 78. Thisoutlet 80 communicates with a correspondingly narrow partiallycylindrical venting channel member 82 (FIGS. 2 and 3) which is welded atits upper end around the circular opening 46 to the bottom wall 45 ofthe box 44.

In this manner spent combustion gases pass from the chamber 36 by way ofthe outlet or discharge passage 80 into the venting channel member S2and thence to the vent pipe 26.

As has previously been indicated, the forward heating element 35, whichis in the nature of a combustion chamber, and the rearward heatingelement 38, which is in the nature of a cool air supplier, are rigidlyconnected together through the welded tubular duct 40 at their lowerends and through the sides of the overlying rectangular box 54 and alsothrough the medium of its bottom wall 45, at their upper ends.

For the purpose of mounting the elements 35 and 38 in the housing orliner 22, the side -walls of the latter are provided with verticalchannel members 85 as best indicated in FIGS. 3 and 5, these channelmembers providing vertical channels 86 for the passage of a portion ofthe air to be heated and taken from the living area of the trailer orother quarters in which the structure is installed. This air entersthrough the bottom of a grill 99 (FIGS. 1 and 2) secured at the front ofthe housing 22. and rises up around the heater unit itl. That air whichrises through the channels 86 serves as an insulating medium to cool theside walls of the housing 22. The channel members 85, which also act assupporting members for the heater unit, carry brackets 92. To thesebrackets there is secured (see FIG. 5) as by means of screws 93 atransverse intermediate supporting and positioning radiation plate 94,this plate being cut away to accommodate the cool air duct 40 at thebottom of the structure and to accommodate the lower end of therectangular box 44 and the spent combustion gases discharge member S2.

For the purpose of mounting the heating unit 20, including the forwardcombustion chamber member 35 and the rearward cool air supplying member38, upper and lower brackets 95 are welded at their opposite ends to thepositioning plate 94 and the back wall 75 of the combustion chamberelement 35. Similarly, upper and lower brackets 95 are welded to theback of the transverse supporting wall or plate 94 and to the front wall5l of the air supplying element 38. When the edges of the transversepositioning or supporting plate 94 are secured to the brackets 92 by thescrews 93, the entire heating unit -is rigidly secured Within thehousing 22, `and in spaced relation to all of the walls of the housing22. Thus, air entering the lower portion of the housing 22 from theliving space within the trailer being heated, rises partly through thelateral air channels 86, and partly up around the forward combustionchamber element 35, both yforward and rearward of the latter. Some ofthe air also passes in behind the supporting and radiation wall 94 andrises up around the air supplying element 38 which gathers considerableheat through the supporting and radiation -wall 94. Air which is heatedconvectionally by the combustion chamber element 3S passes outwardthrough the upper portion ot the grill 99. Radiation heat also passesoutward through grill 90.

For the purpose of better controlling the discharge of the heated airfrom the upper portion of the housing 22, a pair of sloping battles 98and 99 is disposed above the heater unit 2t). The lower battle 98deflects the heated air rising around the combustion chamber element 35outward through the grill 9i). This baiile 98 is disposed between thetwo channel members 85. The upper bale 99, which also is disposedbetween the two vertical channel members 85, cooperates with theunderlying bathe 98 to provide an air discharge through an upper portionof the grill 99 for that portion of the air which rises around the airchamber member 38. The upper baille 99 extends to the back wall of thehousing 22 and thus serves to deect forward above it only that warmedair rising through the air channels 86 at the sides of the heatinginstallation. Both these battles .are notched to accommodate therectangular box 44.

The construction of the burner 42 is not a part of this invention, andany eicient approved gas burner is usable. It includes a control knobl0@ and, if desired, a pilot light and thermostat control. A swingingdoor on cap 102 for controlling access to a lighting hole may also beprovided :as indicated.

In the operation of the present structure, when the burner 42 is inoperation, spent combustion gases rise to the top of the combustionchamber 36 and around the baie 78, whence they pass out through the ventopening and the channel member S2 and thence up through the vent pipe 26to be discharged above the roof. At the same time cold air enters fromabove the roof into the outer air pipe 28 and by Way of the A.annularair passages 30 and 34 from below the vent cap 25. Thence the cold airpasses down into the rectangular box 44 around the lower end of the ventpipe 26 and enters the rectangular passage or port 4S at the top of theair chamber 3S, whence it travels to the bottom of such chamber and fromthat point through the duct 40 into the bottom of the combustion chamber36 to supply the burner 42. By these means, only external air is used tosupport combustion, and air within the trailer is rccirculated over theheating elements for warming the living area of the trailer or otherstructure involved.

This arrangement makes it possible to place a gas heater of theindicated type in an interior wall rather than only in an outside wall.In either instance, the heater is installed between the studs 15 whichare adequately heatinsulated by the various described rising-airpassages between the walls of the housing 22 and the heater elements 35and 38. In such a heater, the height of the combustion chambers 35 andthe air chamber 38, whose individual heights are about equal, is abouttwice their width; and the height of the box 44 extends such over-allheight `about 20% or 25%. For example, in a typical common size, theheight of the elements 35 and 38 is about eighteen inches and theirwidth about eight to nine inches, while the box adds approximatelyanother four inches. Here the thickness of each element 35 and 3S attheir tops is about one inch, and they are spaced about two inchesapart, with the radiation wall 94 disposed about equidistantly betweenthem. This leaves adequate spacing, with a minimum of about one inch,between the heater 20 as a whole `and the walls of the housing 22, which'housing may have a width of about eleven or twelve inches :and a depthof about six and one-half to seven inches. The vent pipe 26 typically istwo inches in diameter, the outer air pipe 28 four inches in diameter,and the intervening radiation pipe 32 three inches in diameter. Thesepipes extend upward from the top of the heater to a position above theroof, and commonly add another live to six feet in over-all height.

It is thus seen that I have provided an improvedsealedcombustion-chamber gas heater for boats, mobile homes, largerhomes, and the like, which makes it possible and desirable to ventgas-tired heaters up through the roof and to locate them in interiorwalls as well as outer walls.

The invention claimed is:

l. In combination in a gas-fired heater:

an upstanding forward heating element providing a vertical combustionchamber to accommodate a gas burner at its lower end and having spacedforward and rearward walls;

a rearward upstanding air chamber element spaced rearwardly from saidheating element and having spaced forward and rearward walls;

:a box rigidly mounted upon both of said elements, and having a rearwardwall substantially vertically aligned with the rearward wall of said air`chamber element and having a forward wall substantially verticallyaligned with the rearward portin of said combustion chamber element,said box having a bottom wall provided with a rst portkcommunicatingwith the combustion chamber and arsecond port communicating with saidair chamber, said box having a top Wall provided with an opening leadingto the interior of said box to supply air thereto;

a vertical vent pipe leading vertically through said opening downthrough saidbox and communicating with y said first port to receivespent gases from said cornbustion chamber;

a vertical air pipe connected to said top said opening for leading airdown through saidrbox to said second port and into said air chamber; and

means connecting thelower` portion of said air chamber elementV to thelower. portion of saidv combustion chamberY element to supply air to thelatter;

2. In combination inra gas fired heater for a housing structure having aroof:

an upstanding heating element providing therewithina combustion chamber;Y

an upstanding ycold air intake element spaced behind said heatingelement and havingparallelrspaced forward and rearward walls providingtherewithin a cold :air chamber` connected with said Vcombustion charmber to supply combustion'air thereto,

said upstanding Velements being spacedk from each other by a separating.air space; Y Y

` :a box directly mounted on the ments in sealed relationship therewithand spanning said separating space, said box havingl top, bottom andside walls enclosing an -air space, Y v the bottom wall of said boxbeing attached'directly to the top rearward portion of the cold airintake element and also being attached directly to a top portion oftheupstanding heating element,

said box and cold air element having between them an =air portconnecting ,saidcold airY chamber with ,said

air space in saidbox to supply down-draft cold airV lwall around mp` ofboth of said ele- Vtoisaid coldy air chamberand said combustion chamber;A exhaust duct means leading'from said combustion charnber through saidbottom wall `and said topfwall of said box, and said air space in saidbox being Vin sealed relation with said exhaust. duct means and saidcornbustion chamber; l Y and ycold air duct meansv at said top wallaround said exhaust duct'rneans providing a cold air intake passagearound said exhaust duct meansy into said air space. n 3. A combinationas in claim 2 including an upstanding radiation partition plate intheseparating air space between said elementsY and closely/.underlying saidbox.

4. A-combination as in claim 2 wherein the points of attachment of saidbox to said cold air intake element and to said-heati11gelen1ent aresubstantially in the same horizontal plane; g ,Y Y

5. A combination as in claim 2 including an external housing in whichsaid upstanding elements are mounted, said housing providing for hot airdistribution therefrom.

6. A combination as in claim 2 including an upstanding partition platesecured to said elements and upstanding in said separating air space,and an external housing in which said upstanding elements are mounted,such housing and the upstanding edges of Said plate being connected forsupporting said elements. n

' References Citedin thele Vof this patent 3,082,758 '-,Heiman L Man26,V 1963

1. IN A COMBINATION IN A GAS-FIRED HEATER: AN UPSTANDING FORWARD HEATINGELEMENT PROVIDING A VERTICAL COMBUSTION CHAMBER TO ACCOMMODATE A GASBURNER AT ITS LOWER END AND HAVING SPACED FORWARD AND REARWARD WALLS; AREARWARD UPSTANDING AIR ENAMBER ELEMENT SPACED REARWARDLY FROM SAIDHEATING ELEMENT AND HAVING SPACED FORWARD AND REARWARD WALLS; A BOXRIGIDLY MOUNTED UPON BOTH OF SAID ELEMENTS, AND HAVING A REARWARD WALLSUBSTANTIALLY VERTICALLY ALIGNED WITH THE REARWARD WALL OF SAID AIRCHAMBER ELEMENT AND HAVING A FORWARD WALL SUBSTANTIALLY VERTICALLYALIGNED WITH THE REARWARD PORTION OF SAID COMBUSTION CHAMBER ELEMENT,SAID BOX HAVING A BOTTOM WALL PROVIDED WITH A FIRST PORT COMMUNICATIONWITH THE COMBUSTION CHAMBER AND A SECOND PORT COMMUNICATING WITH SAIDAIR CHAMBER, SAID BOX HAVING A TOP WALL